Electrical connector



Sept. 20, 1955 F. w. HARRISON ELECTRICAL CONNECTOR Filed Jan. 5, 1953INVENTOR.

FRANCIS W. HARRISON nite d ms atentfO 2,718,625 PatentedSept. 20, 1955"1 t 2 a Figure 4 a top view of a modified .form of the in- Iventioii,showing the multi-unit connectonand i Figure 5 is a view partly inelevation and partly in gr-71851625 section taken alongjthe line 5-5 ofFigure ELEGTRIGALQGNNEQTQR 5 While .the invention .herein will 'bedescribed .as serv- Francisw.iinnsas, neaenask,iv.I. Application January5, 1953, Serial No. 329,755

1 Glaim; ((31-339-498) v (Granted under'Titl'e 35, usscade (1952), sec.266) I The present invention relates fo-tlieassembly -of tni'niaint-etubes'to'printed circuits. lathe assembly ofpiinted "circuits, itishecessary that the leads 1 miniature "tubes be secured to the printedcircuitry formed on the chassis of the printed circuit assembly.

In the past, various methods and devices have been used to accomplishthis end. One method used was to solder the fine flexible tube leads tothe printed circuitry. Such method has been found objectionable in thatin the event of the failure of any one tube or tubes the task ofremoving and severing the solder connection was difficult and oftendestructive to the remainder of the printed circuitry.

In an attempt to overcome the disadvantages of such types ofconnections, various tube sockets have been devised for use in securingleads of subminiature tubes. Typical of such is an electrical socket forminiature tubes including basically a spring-like contact having tworesilient arms wherein the lead or prong of the tube is forced betweenthe resilient arms, making contact through but a small portion of theentire length of the resilient arms.

It has been found that in the utilization of a socket of the typedescribed above, considerable difliculty is encountered in the insertionof the extremely fine flexible leads which usually have a diameter offrom .015 to .019 inch. It has been found that the wire leads, due totheir flexibility, do not readily lend themselves for insertion intoconventional sockets such as described above. It has also beendiscovered that such a socket due to its form of construction providesonly low mechanical retention and small electrical contact between thelead wires and the socket. It has also been found that considerableflaking of the contacts occurs during insertion and withdrawal of thewire leads, which has proven to have a deleterious eifect.

The primary object of this invention is to provide a connector for thefine leads of miniature tubes wherein the leads of such tubes can beeasily inserted and electrically secured in said connector.

Another object of the present invention is to provide a connector forthe leads of miniature tubes which will provide good electrical contactover a relatively large surface.

Another object of the invention is to provide a connector that willpermit good mechanical contact between the wire leads and the connector.

The invention can best be understood from the following description tobe read in view of the accompanying drawing in which:

Figure 1 is a cross sectional view showing the connector, its associatedspring retention pin in position within the connector and a partialelevational view of a miniature tube;

Figure 2 is an elevational view of the spring retention pin alone,removed from the connector;

Figure 3 is a view partly in section and partly in elevation taken alongthe line 3-3 of Figure 1;

ing as .a connector for miniaturetubes in printed circu itry wherein itserves as .a means for mechanicallyand electrically securing the thinflexible leads-of said tubes, i'tIis 'to'be understood that'theconnector can have other applications. p

Referring to the modifications'hownin Figures '1', 2 and '3 .of the-drawing, there is shown a chassis .1'1 of nonconductive material, theunderside ofwhich is provided with a section of printed circuitry shownat .12. .Extending .tran'sversely through and rigidly fixed Yin.an'opening I14} .iu the chassis 1'1, andmakin'g electrical contact withthe printed circuitry his a stud .1 3 made-of .a conductive materialsuch as brass or copper. The stud 13 is held in place by being forcedinto and through opening 14 in the chassis 11 which has a diameterslightly smaller than that of the stud 13. Electrical engagement betweenthe stud 13 and the circuitry 12 is efiected by placing the stud througha cutout in the printed circuitry, which cutout is in register with theopening 14. The stud 13 comprises a rounded knob portion 15, whichintimately engages the printed circuitry making electrical contacttherewith and a tubular shank portion 17.

Secured or adjacent to the top side of the chassis 11 is a miniaturetube 19. The method of afiixing, retaining or securing the tube 19 inposition forms no part of this invention and is therefore described inno further detail. Extending from the base of the tube 19 are a numberof leads, one of which is shown as 21. As pointed out above, the leadsof such tubes are made of extremely fine flexible wire of from .015 to.019 inch in diameter which are required to be brought into electricalcontact with the printed circuitry on the underside of the chassis. Thisis accomplished by inserting the lead 21 into the tubular shank portion17 of the stud 13. This can be easily accomplished as the diameter ofthe shank portion of the stud is many times greater than that of thelead 21. For retaining the lead 21 within the tubular shank portion ofthe stud and firmly wedging the lead against the inner surface of saidstud, there is provided a retaining pin 23. The pin 23 comprises a headportion 25 and two opposing flat metallic flexible spring arms 27. Thearms 27 are preferably made of a single strip of springy metal which ismedially bent, at which point it is confined in the head portion 25 byany suitable means such as a blob of solder 28 which also aids inkeeping the arms 27 apart. Due to the nature of the spring arms 27, saidarms together normally assume a diamond shape as shown in Figure 2.However, when the pin 23 is inserted into the tubular shank portion 17,as shown in Figure 1, the arms will exert pressure against the lead 21,thereby confining the lead securely within the tubular shank portion ofthe stud.

In the modification shown in Figures 4 and 5, there is shown theconnector of the present invention as applied to a multi-connector unit.In the specific embodiment shown in Figures 4 and 5, the chassis 30carries a section of printed circuitry 32 on its underside. Positionedwithin openings 34 of the chassis 30, preferably aligned in somedefinite configuration to suit any particular need, are a plurality ofmetal grommets 39, held by a blob of solder 41, which electricallyengage the printed circuitry 32 through cutouts in the circuitry aspointed out above. A miniature electronic tube 43 is shown afiixed tothe chassis 30 by any conventional means. Extending from the bottom ofthe tube are a plurality of fine metallic leads 45 such as are common tosuch types of tubes as described supra. For electrically connecting theleads 45 to the printed circuitry 011' the underside of said chassis,

the various leads are'placed in appropriate grommets 39. For holding theleads securely within the grommets 39, there is provided abar 47 whichutilizes generally the samebasic principle' as was used in securing asingle and separate lead as was desc 'bed 'in connection with Figure l.The retention bar comprises a plate 49 made of a non-conductive materialsuch as plastic, and having a series'of fopenings 51' in which arerigidly secured a number of' sipring pins 53 similar in design to thepins 23. The pins SS'difiEer' slightly from pins '23 in omitting thehead'portion 25, and in lieu thereof the medial bent portion of thearms'is confined within an opening in the plate 49 by separate blobs ofsolder 55 which also serve to keeptlie ar'msof the pins apart. It willbe obvious that 'for." any particular installation the pins 53 willassume the sameconfiguration in the plate 49 as the grommets '39in'chassis 30. After the leads of the tube are placed into the grommets39, the pins 53 are placed into respective grommets 39 and the leadswill be confined by the pressure exerted by the arms'of the pin upon theleads of the tube.

What is claimed as new is:

For electrically engaging the r electronic tube to an electric cielatively fine leads of an rcuit, means comprising a panel, a pluralityof electrically conductive grommets mounted in said panel said circuit,and a detachable and in electrical engagement with bar having aplurality of pins secured thereto and extending therefrom for securingsaid leads within sai d grommets, each of said pins comprising twoelongated spring-like arms-which when confined in each of said grommetsexert pressure against substantially the entire len grommet.

References Cited in the file of this patent UNITED STATES PATENTS StoneApr. 27,

gth of said lead confined in said

